I have not bought an inverter charger yet, but I plan to. But I don't want the inverter automatically turning on when shore power is lost. That will being draining my batteries while perhaps powering devices I do not want it to. I only want to (manually) turn the inverter on just before I use the microwave and then I'll turn it back off.
To put it another way - I want to be able to leave the camper, while powering AC devices inside from shore power, knowing that if shore power is lost my batteries won't be discharged. I do not need any kind of Uninterruptible Power Supply features.
Is this possible? I see the "UPS Function" setting, that sounded like exactly what I want, but when I looked it up that setting is something about the quality of power at which it will switch over.